Control of protozoa and protozoan cysts that harbor legionella

Abstract

A method of controlling protozoa trophozoite and cysts is disclosed, comprising administering a phosphonium salt of the formula: (R 1 ) 3 P − R 2 .X − , wherein R 1 is an alkyl group having from 1-8 carbons and R 2 is a chain substituent having 6-20 carbons, to aqueous systems harboring protozoa trophozoites and cysts. Addition of such phosphonium salts to aqueous systems was found to be effective at killing both the protozoa trophozoites and cysts. By effectively killing both the protozoa trophozoites and cysts, organism such as Legionella cells harbored in both the trophozoites and cysts are killed.

What is claimed is:  
     
       1. A method of controlling protozoa trophozoites and cysts comprising exposing said protozoa to an effective amount for killing said protozoa trophozoites and cysts of a phosphonium salt of the formula: 
       
         
           (R 1 ) 3 P + R 2 .X −   
         
       
       wherein R 1  is an alkyl group having from 1-8 carbons, R 2  is an n-alkyl group having from 6-20 carbon atoms and X −  is an anion selected form the group consisting of halides, sulfates, nitrates, nitrites and mixtures thereof. 
     
     
       2. The method of  claim 1  wherein said protozoa are in the trophozoite form. 
     
     
       3. The method of  claim 1  wherein said protozoa are in the cyst form. 
     
     
       4. The method of  claim 1  wherein said protozoa contain Legionella type bacteria. 
     
     
       5. The method of  claim 1  wherein X −  is selected from the group consisting of is Cl − , Br − , SO 4   = , NO 3   = , NO 2   − , I −  or mixtures thereof. 
     
     
       6. The method of  claim 1  wherein said phosphonium salt is added in a treatment concentration of from about 0.1 to 100 micrograms per milliliter. 
     
     
       7. The method of  claim 1  wherein said phosphonium salt is Tri-n-butyl-tetradecylphosphonium chloride.